1. Field of the Invention
Aspects of the present invention relate to a plasma display device and a driving method thereof. Aspects of the present invention relate to a plasma display device and a driving method where input grayscales are converted and the number of on-subfields and useable subfields corresponding to the grayscales of input videos are increased to enhance discharge characteristics and reduce false contours.
2. Description of the Related Art
A plasma display device is a display device that uses plasma generated by a gas discharge to display characters or images. In a plasma display device, a video signal of one frame is divided into a plurality of subfields respectively having a weight. Gray scales are expressed by a combination of the subfields of different weights. Each of the subfields include a reset period, an address period, and a sustain period. The reset period is for initializing the states of each discharge cell so as to facilitate an addressing operation of the discharge cell or cells. The address period is for selecting turn-on/turn-off of the discharge cells (i.e., discharge cells to be turned on or off) and accumulating wall charges in the discharge cells (i.e., the addressed discharge cells) that are in the turn-on state. The sustain period is for causing a discharge for displaying of an image using the addressed discharge cells.
However, when an input video signal data of the one frame is divided into a plurality of subfields and grayscales are displayed according to the on/off of the subfields as describe above, a false contour may be generated due to human vision properties. That is, when a moving image is displayed, a false contour phenomenon may occur in which a grayscale that is different from an actual one is perceived by human eyes because of the vision properties of the human eyes that follow the movement of the image.
In addition, when the number of the turned-on subfields is small when the grayscales are displayed according to the on/off of the respective subfields, a small amount of priming particles is generated. Accordingly, a discharge may not be sufficiently generated.